Original fixes in c169dcb5221cf3dd452c291bf97374bb459cc5b9; didn't get merged in 39cad55711897323fac5f651c003c4d815a51ae0 because the code had been broken out to another file, but manual merge went smooth.
These affect twitterstatusfetcher.php on all 32-bit installs and some 64-bit installs (depending on whether the version of the JSON library reads the large numbers as long or double internally). 64-bit bug is harder to see as it tends to manifest as off-by-one due to losing a bit of precision off the end.
ea31051401